how to parallel Ferrite transformers to get more power

[Mohammedhanafy]

hi all

i'm working on a 12vdc 220vac power inverter and just want to know how to parallel more than one ferrite transformer to get more power at the DC-DC stage which is 12vdc to 340vdc

 

[chuckey]

You could wind two transformers and connect them in series or parallel. This will double/halve the Lm, leakage inductance Lp Ls etc. Any slight miss count of the ratios will have a dramatic effect, i.e. if one winding is 150 turns on one transformer and 149 on the other. That is why if you are using toroids, just stack them, one on top of the other and wind them as one core. This keeps the number of turns spot on.
Frank

 

[Mithun_K_Das]

If you wish to make a bus bar and use more ferrite transformers to increase the power then its easy to make a parrel with 5 transformers connection among them in this way,

Transformer1===> Bridge===>Rectifier===> Inductor (just handmade, around 100uH)===> Bus Bar
Transformer2===> Bridge===>Rectifier===> Inductor (just handmade, around 100uH)===> Bus Bar
.
.
.

Transformer5===> Bridge===>Rectifier===> Inductor (just handmade, around 100uH)===> Bus Bar

But you must ensure that each of the transformer can generate the same voltage (say 310V).

 

[Mohammedhanafy]

chuckey : Thanks for your response and i got what You said .. and for that i will test every transformer individually to make sure it's the same as others .

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Mithun_K_Das:

thanks alot but i just didn't get how to connect them or i think u mean other topology than Push-Pull where the primary will be driven by mosfets and 12v battery then the output is recified by Fast Recovery Rectifiers... then a 320vDC is feed to H-Bridge circuit in order to get a 220vac output

 

[Orson Cart]

if you wish to use >1 transformer it is a good idea to put the driven side in series and the o/p side in parallel (a separate bridge rectifier for each in your case) this gives good sharing even with small differences in the transformers

 

[chuckey]

Like it Orson!
Reminds me, I went to school near a pub called the "Horse and Wells", bus conductor always shouted " Orson wells " (Very Famous film actor /director. . .)
Frank